Chapter 4

Cell Structure and Function

What are Cells?
Overview Cells are the foundational level of organization of life. An organism may be unicellular, as with prokaryotes and most eukaryotic protists,…
Cell Size
4.2: Cell Size
The size of cells varies widely among and within organisms. For instance, the smallest bacteria are 0.1 micrometers (μm) in diameter—about a…
Eukaryotic Compartmentalization
4.3: Eukaryotic Compartmentalization
One of the distinguishing features of eukaryotic cells is that they contain membrane-bound organelles—such as the nucleus and…
Prokaryotic Cells
4.4: Prokaryotic Cells
Prokaryotes are small unicellular organisms in the domains Archaea and Bacteria. Bacteria include many common organisms such as Salmonella and…
The Nucleus
4.5: The Nucleus
The nucleus is a membrane-bound organelle that contains a eukaryotic organism’s genetic instructions in the form of chromosomal DNA. This is…
Ribosomes
4.6: Ribosomes
Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells…
Microtubules
4.7: Microtubules
There are three types of cytoskeletal structures in eukaryotic cells—microfilaments, intermediate filaments, and microtubules. With a diameter…
Mitochondria and Peroxisomes
4.8: Mitochondria and Peroxisomes
Mitochondria and peroxisomes are organelles that are the primary sites of oxygen usage in eukaryotic cells. Mitochondria carry out cellular…
The Extracellular Matrix
4.9: The Extracellular Matrix
Overview In order to maintain tissue organization, many animal cells are surrounded by structural molecules that make up the extracellular matrix…
Tissues
4.10: Tissues
Cells with similar structure and function are grouped into tissues. A group of tissues with a specialized function is called an organ. There are four…
Biology: Studying Mitochondria in Drosophila Ovaries
4.12: Biology: Studying Mitochondria in Drosophila Ovaries
A thorough understanding of mitochondrial regulation requires an understanding of the structure-function relationship. In this article, genetic…
Chemistry: From Constructs to Crystals
4.13: Chemistry: From Constructs to Crystals
β-barrels perform important functions within the outer membranes of Gram-negative bacteria, mitochondria, and chloroplasts. However, obtaining…
Developmental Biology: Structure-function Studies in Mouse Embryonic Stem Cells
4.14: Developmental Biology: Structure-function Studies in Mouse Embryonic Stem Cells
Proteins often contain multiple domains that carry out different functions. However, studies that entirely eliminate them can not distinguish such…
Immunology: Isolation of Exosomes from the Plasma of HIV-1 Positive Individuals
4.15: Immunology: Isolation of Exosomes from the Plasma of HIV-1 Positive Individuals
Exosomes are extracellular vesicles that are involved in HIV pathogenesis. Studying their role in this disease requires separating them from HIV…